Heat exchanger



July 7, 1931. c. w. METZGAR I HEAT EXCHANGER Filed Nov. 22, .1928

ATTORNEY.

I Patented July 7, 1931 UNITED STATES PATENT OFFICE] CHESTER W. METZGAE,F EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEYCITY, NEW JERSEY, A CORPORATION OF NEW JERSEY HEAT EXCHANGER Applicationfiled. November 22, 1928. Serial no. 321,151.

This invention relates to heat exchange apparatus, and more particularlyto devices adapted to be used in conjunction with compressors forcooling the air between stages 3' of compression or between thefinalstage of compression and the storage receiver.

One object of the invention is to obtain a compact and eflicient coolingunit in which liquid conveying tubes may be arranged in close proximityto the walls of the heat exchanger.

Another object is to avoid the formation of what may be termed dead airpockets in the heat exchanger by means adapted to insure a stateofturbulence in the heat exchanger so that the fluid intended to becooled will be brought into repeated and intimate contact with thesurface of the cooling tubes.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawings illustrating a practical application of the inventionand in which similar reference characters refer to similar parts,

Figure 1 is a longitudinal vertical section of a heat exchangerconstructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken so through Figure 1 on the line 2-2looking in the direction indicated by the arrows,

Figure 3 is an enlar ed detail sectional elegation of one end 0 a heatexchanger, an

Figure 4 is a transverse view taken through Figure 1 on the line 44looking in the direction indicated by the arrows. Referring moreparticularly to the drawings, A designates generally a heat exchangerhaving a casing B in which is disposed a group of cooling liquidconveying tubes C. The casing B comprises in this instance a tubularsection D to one end of which is secured a head E and at the other endan extension F of substantially the same diameter as the tubular sectionD to accommodate a group of cooling tubes C. A 010- sure is provided forthe outer end of the extension F in the form of a cover or head G whichmay be secured to the extension F in any suitable manner, as forinstance by bolts H.

For convenience of illustration, only a single pass cooler isillustrated. It will, however, be apparent to those skilled in the artfrom the following description that the invention is also applicable tomulti-pass coolers or heat exchangers.

According to the construction shown, the element intended to becooled,'such as pressure fluid issuing from a compressor, enters thecasing B through an inlet opening J formed in this instance in theextension F. The pressure fluid therefore enters one end of the heatexchanger and is caused to flow through the casing B along a serpentinepath formed by baffles K which are in this instance disposed instaggered relationship with respect to each other throughout the acasing to cause the fluid to be brought well into contact with thesurfaces of the cooling tubes C.

Any suitable number of bafiies may be provided for the purpose describedand these baflles are so spaced with respect to each other and the sidesor ends L of the baflies K over which the pressure fluid flows arepreferably so spaced with respect to the bounding surface of the casingthat substantiallythe same pressure may exist through out the entirearea of the heat exchanger. In other words, the space between the ends Lof the baflles K and the wall of the casing is preferably such thatthere is neither a substantial decrease nor increase in the pressure ofthe fluid during its course through the exchanger A.

After passing over the bafie K adjacent the head E of the heatexchanger, the pressure fluid will flow against a grid or separator Oforming in this instance an inte- (g)ral portion of the head E. Theseparator may be in the form of a series of ribs P which, when thepressure fluid contacts therewith, will have the efiect of extractingmoisture from the pressure fluid immediately before the exit of suchpressure fluid through an outlet opening Q of the head E.

The ribs P may be arranged in any suitable manner in oppo ite sides0f-the head E and between the opposed series of ribs, P

and on the bottom of the head E is a bridge 'jected, it is essentialthat means be provided to accommodate .the free elongation and contractional movement of thetubes C. To this end the tubes are seated withone end in a tube plate V fixedly secured to the head E and at the otherends are inserted in what may be termed a movable tube plate W. The tubeplate W lies within the confines of the casing and is preferably ofsufliciently smaller diameter to enable it to move freely longitudinallyof the casing in accordance with the degree of contraction and expansionof the tubes which it supports.

Secured to the tube plate V is a head X for cooling liquid, such aswater, and into which the Water may be conveyed through a pipe Y leadingfrom a suitable source of supply. The water is preferably introducedinto the head X at a point near the uppermost 1portion of the said headX and may flow t rough a series of tubes C lying in the upper region ofthe heat exchanger and thence into a head Z bolted to the tube plate Wor otherwise suitably securedthereto and forming a chamber I) throughwhich Water may flow into lower rows of tubes and again be returned tothe head X. The chamber In in the head Z and a chamber 0 in the head Xmay be suitably divided into any desired number of compartmentswherewith adjacent rows of tubes 0 may communicate so that the directionof the flow of water may be repeatedly reversed until finally it reachesthe lowermost portion'of the head X from whence it may be conveyed bymeans of a pipe d.

In apparatus of this character it is desirable that substantially allthe available space in the casing B be occupied by the cooling means,such as the tubes C in order to avoid the formation of dead air pocketsin which pressure fluid of any temperature may remain substantiallymotionless and thus act as an insulator to preclude any additionalcooling effect which might otherwise take place due to the temperatureofthe atmosphere surrounding the heat exchanger. The present invention.contemplates the elimination of such dead air pockets and to this endthe head Z is provided at its edge with an annular flange e of onlysmall width in order that the chamber b for which the flange 6 forms abounding surface may be in diameter only slightly smaller than thediameter of the casing B. The flange e in'this instance is adapted toencircle a boss f of the tube plate W and agasket 9 is disposed betweenthe flange e and the tube plate W to seal the chamber b. By forming theflange e in the manner described the means whereby the head Z is securedto the tube plate W, such as the bolts 71, are insterted through thehead Z at points within the inner surface of the flange 6. Thisarrangement will permit of the disposal of cooling tubes C at pointsclose to the casing and therefore throughout substantially the entirearea of the casing.

Formerly, in heat exchanging apparatus it has been customary to dependentirely upon the natural flow of the pressure fluid through the heatexchanger to cause agitation of the pressure fluid so that it may beuniformly distributed throughout the heat exchanger and brought intocontact with the entire available cooling surfaces of the tubes C. Whilethis was the desired result, it was found that in practice the mainfluid stream followed the serpentine course hereinbefore referred to andthat there were considerable areas in the casing in which pressure fluidremained comparatively dormant, thus insulating not only the casing ofthe heat exchanger but also considerable areas of the cooling tubes C.In order therefore to insure a desirable state of turbulence throughoutthe entire area .of the casing, the baflles K are provided with passagesj for diverting a portion of the pressure fluid from the main fluidstream. The pressure fluid enters the passages j from the upstream sideof the baffles and injects such pressure fluid laterally into the mainfluid stream to insure its thorough agitation so that the pressure fluidcomprisingthe main fluid stream will not only flow along its generalcourse towards the outlet opening Q, but will be diffused and willtherefore be brought into repeated contact with the surfaces of thecooling tubes C. The passages 7' may be of any suitable number andconformation and are preferably located on diametrically opposite sidesof the tubes C, and for convenience ofrmanufacturing, they alsopreferably open into apertures in the baflles K through which the tubesC extend. The apertures 70 are of such diameter that the walls thereofmay be in body contact with the tubes so that the tubes may be suitablysupported at points intermediate their ends.

The operation of the device is as follows: Assuming the machine, such asa compressor, to which the heat exchanger may be attached to be inoperation, compressed fluid entering the inlet opening J will -flow overthe ends L of the bafiies K through the casing B and into the head Ewhere, upon striln'ng the ribs, P, S and T of the separator, anymoisture or other matter entrained by the fluid will be separated fromthe fluid. This scouring process preferably takes place just before thefluid leaves the casing through the outlet opening Q, from whence it mayflow to a storage receiver, where only one unit is being utilized or, incase of a two pass exchanger, into the connected unit.-

During the course of the fluid through the casing B, fluid will enterthe .passages j on the up-stream side of the baflies K and" will flowthroughth'e'passages to be again injected in a longitudinal directionrelativel5 1y to the casing into the main fluid stream. In this *way thefluid will be thoroughly agitate d to prevent the undesirable insulatingefi'ect hereinbefore referred to.

I claim:

1. A heat exchanger, comprising a casing, tubes in the casingforconveyin .cooling liquid, baflies in the casing arran e in stag geredrelation with respect to eachother to I,

direct fluid flowing through the easing into 3 intimate contact with thetubes, and a separator integral with the casing for removmg' moistureentrained by the fluid intended .to

be cooled.

ing and inject it laterall into t e main stream for agitating the fluidand thus insure its intimate contact with the tubes.

6. A heat exchanger, comprising a casing,

baflies in the casing having apertures therein, liquid conveying tubesextending through the apertures, said tubes being supported againstlateral movement intermediate their ends by the bafiles, and separatepassages for each tube in the baflles adjacent 'the apertures andcoalescing therewlth to divert a portion of the fluid flowing throughthe casinto the main stream for agitating the uid and thus insure itsintimate .contact'with the'tubes.

In testimony whereof I have signed this specification.

2. A heat exchanger, comprising a casing having an inlet and an outletopening, tubes in the casing for conveying cooling liquid 7 through thecasing, baflles in the caslng,fpassages in the baflles to direct aportion 0 the fluid intended to be cooled longitudinally of the casingand in the direction of the outlet opening to agitate the main fluidstream and insure its intimate and repeated contact with the tubes, anda separator integral with the casing and in the same transverse plane asthe outlet opening for removing moisture entrained by the fluid intendedto be cooled.

3. A heat exchanger, comprising a casing,

tubes in the casing, for conveying cooling 4 liquid, a tube plateaflixed to the casing for supporting the tubes at one end, a movabletube plate in the casing to support the-ops -posite ends of the tubesand having a boss,

a head for the movable tube plate, a flange on the head to form achamber for cooling hquid and encircling the boss to seal the chamber,and means lying within the inner surface of the flange for securing thehead to the movable tube sheet.

4. A heat exchanger, comprisin a casing, tubes in the casing for conveyng cooling liquid, a tube plate aflixed to the casing for supporting thetubes at one end, a movable tube plate in the casing to support theopposite ends of the tubes, a head for the movable tube plate having anannular flange to form a chamber for cooling liquid, and bolts lyingwithin the inner surface of the flange for securing the head to themovable tube plate.

